Flash lamp signaling circuit employing logic signal activation

An integrated circuit chip for use with a given voltage supply for sequentially flashing a plurality of photolamps responsive to either a low trigger signal having a voltage level equal to or less than the supply voltage or a high trigger signal having a voltage level greater than the supply voltage, said chip comprising:

• a pair of supply terminals configured for electrical coupling to the voltage supply so as to energize said chip;
• a lamp firing circuit coupled to said supply terminials and configured for sequentially firing each of a plurality of photolamps in a predetermined order responsive to repetitive application of a given input signal, said lamp firing circuit including a plurality of lamp switching circuits coupled to said supply terminals in a predetermined order of first to last with each of said switching circuits being configured for electrical coupling to one of the photolamps, and a forward sequencing circuit coupled to each of said lamp switching circuits, said sequencing circuit being configured for actuating the next in order of said switching circuits having an operable photolamp responsive to said given input signal;
• a plurality of trigger circuit elements configured for connection in a first or second trigger circuit configuration to said forward sequencing circuit for respectively providing said input signal responsive to application of the high and low trigger signals, said trigger circuit elements including a voltage detector configured for connection with a first group of said elements in said first trigger circuit configuration to provide said input signal responsive to application of a trigger signal exceeding the supply voltage, and a transistor independent of said first group of elements configured for connection in said second trigger circuit configuration to provide said input signal responsive to application of a trigger signal equal to or less than the supply voltage.